I have had this problem for several weeks and I have seen others having the same problem. The files get up to 500 GB . I delete them but they reappear about a week later. I have tried completely reinstalling Avast. Surely there is something wrong with the software, irrespective of whether debug log is ticked or unticked. Windows + X, Powershell as Admin, wpr -cancel seems to stop the process and get rid of the files (very slowly) but effect does not seem to be permanent.